Hypothesis: Differentiation Teaches You What You Do
Feldenkrais differentiation works because it allows you to become aware of separate, distinct processes within a single movement. Not necessarily individual muscles — processes. You become aware of what you actually do. It isn't that you walk out of a lesson and then keep track of every angle of every joint throughout the day. But somehow, bringing something to the forefront of your awareness changes, refreshes, reminds, opens your idea of yourself, your map of yourself.
And this means you have options. More than one way to do a single movement, for sure! By bringing a very precise attention to what you do, you suddenly open up an infinite number of possibilities that are appropriate to you.